Radiographic image capturing system

ABSTRACT

A radiographic image capturing system includes: a radiographic image capturing apparatus which wirelessly transfers a signal value read from each of a plurality of radiation detecting elements; a channel switch controlling device capable of switching a channel used for wirelessly transferring the signal value from the radiographic image capturing apparatus to another channel; a notifying device which gives a notice to an operator who operates the radiographic image capturing system; and a display device which displays a radiographic image generated based on the signal value transferred from the radiographic image capturing apparatus, wherein the notifying device notifies an operator of the fact that the channel is being switched, at least once, while the radiographic image capturing apparatus is switching the channel.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to radiographic image capturing systems,in particular, to a radiographic image capturing system that transfersdata from a radiographic image capturing apparatus through a wirelessnetwork.

Description of Related Art

Radiographic image capturing systems have been developed that captureradiographic images with radiographic image capturing apparatuses (flatpanel detectors) each including multiple radiation detecting elements(see multiple radiation detecting elements 7 in FIG. 2, which will bedescribed below). Each radiation detecting element generates electriccharges in proportion to the dose of radiation emitted. The radiographicimage capturing apparatus reads the electric charges as signal values.The radiographic image capturing system transfers the signal values readat the radiographic image capturing apparatus to a console whichgenerates a radiographic image based on the signal values.

The signal values may be transferred from the radiographic imagecapturing apparatus to the console through a wired network, i.e., over acable connecting the radiographic image capturing apparatus and theconsole, or through a wireless network.

For example, imaging is performed with the radiographic image capturingapparatus in an imaging room in a facility, for example, a hospital, orin a sickroom to which a medical cart equipped with the console and aradiation generating apparatus and the radiographic image capturingapparatus are moved, as described below. During the imaging, theradiographic image capturing apparatus and the console may be connectedwith a cable. Such a connection, however, may cause a radiologicaltechnician to stumble over the cable, precluding smooth imaging. Toavoid this problem, the communication between the radiographic imagecapturing apparatus and the console is performed through a wirelessnetwork in many cases.

In recent years, much more opportunities are available to use wirelesscommunications in medical equipment, in-hospital equipment, such asradiology information systems (RISs), or in-hospital networks. During awireless transfer of the signal values from the radiographic imagecapturing apparatus to the console, as described above, suchcircumstances often cause interference between the transfer of thesignal values and wireless communications from other equipment in achannel used to transfer the signal values.

For example, Japanese Patent Application Laid-Open Publication No.2015-58077 discloses a radiographic image capturing system whichidentifies a wireless communication device that causes interference withsignal values transmitted from a radiographic image capturing apparatus(referred to as an “electronic cassette” in this Patent Literature). Ifsuch a wireless communication device is identified, the radiographicimage capturing system restricts the communications from the wirelesscommunication device to prioritize the transfer of the signal valuesfrom the radiographic image capturing apparatus to the console. Therestrictions of communication include, for example, stop ofcommunications, restriction of the data rate (i.e., the volume oftransferred data per unit time), and channel switching.

Actually, it is not so easy to restrict communications from otherwireless communication devices to prioritize the wireless transfer ofthe signal values from the radiographic image capturing apparatus to theconsole in many cases, as described above. For example, IEEE802.11a, awireless LAN standard, requires to avoid interference with radio wavesfrom predetermined radar, such as a weather radar, through dynamicfrequency selection (DFS), in other words, to take action to avoidinterference with detected interference waves from radars.

Unfortunately, Japanese Patent Application Laid-Open Publication No.2015-58077 cannot successfully restrict interference waves from apredetermined radar when such interference waves are detected during thewireless transfer of the signal values from the radiographic imagecapturing apparatus to the console, for example, over a 5 GHz bandchannel.

Many hospitals and other medical facilities preliminarily selectnon-overlapping channels in the 2.4 GHz or 5 GHz band and use thesechannels to perform wireless communications over a wireless LAN betweenin-hospital medical instruments or devices on in-hospital networks.

For example, during imaging in the imaging room in the hospital or thelike as described above, various wireless communication devices otherthan the in-hospital medical equipment or those on the in-hospitalnetworks may perform wireless communications over various channels inthe vicinity of the imaging room. Despite the selection of channels usedfor communications between different medical instruments to avoid anoverlap of channel frequencies, as described above, the channelfrequencies for the medical instruments in the imaging room may overlapwith those for wireless communication devices other than the medicalinstruments used in the vicinity of the imaging room, causing radiointerference.

For example, during imaging in a sickroom to which the radiographicimage capturing apparatus and a medical cart equipped with the consoleand the radiation generating apparatus are moved, as described above,another wireless communication device may also perform wirelesscommunications in the sickroom or in the vicinity thereof over variouschannels. This situation may result in an overlap of channel frequenciesbetween the medical instruments and another wireless communicationdevice, resulting in radio interference.

In particular, these issues become more problematic when the medicalcart equipped with the console is moved to different sites in a hospitalfor imaging. The channels used by wireless communication devices otherthan the medical equipment vary, depending on in-hospital places. Thismeans that channels causing radio interference also vary, depending onin-hospital places. More specifically, a wireless transfer of signalvalues from the radiographic image capturing apparatus to the consoleover a particular channel in one in-hospital site (for example, asickroom) may not cause radio interference, while a wireless transfer ofthe signal values over the same channel in the other site to which themedical cart is moved may cause radio interference with other wirelesscommunication devices.

For example, during the transfer of the signal values from theradiographic image capturing apparatus to the console, the channel usedto transfer the signal values may have radio interference with otherwireless communication device. Such radio interference may require thechannel used to transfer the signal values from the radiographic imagecapturing apparatus to the console to be switched to another channel.Such channel switching normally involves a temporary suspension of thetransfer of the signal values for about one minute.

Unfortunately, a radiological technician may fail to notice such channelswitching. Such a failure may hinder the operations of the radiologicaltechnician because the radiological technician does not know the reasonwhy the transfer of the signal values is being suspended. Theradiological technician may mistakenly believe that the cause of thesuspension of the transfer lies in a defect of the system and perform anunnecessary operation or processing, which may prevent a properimplementation of operations.

SUMMARY OF THE INVENTION

An object of the present invention, which has been made to overcome thedisadvantages of the conventional techniques described above, is toprovide a radiographic image capturing system that provides anopportunity for a radiological technician to properly know that achannel used for a wireless transfer of signal values from theradiographic image capturing apparatus is under the switching operation.

To achieve the above object, a radiographic image capturing system inwhich one aspect of the present invention is reflected includes: aradiographic image capturing apparatus which wirelessly transfers asignal value read from each of a plurality of radiation detectingelements; a channel switch controlling device capable of switching achannel used for wirelessly transferring the signal value from theradiographic image capturing apparatus to another channel; a notifyingdevice which gives a notice to an operator who operates the radiographicimage capturing system; and a display device which displays aradiographic image generated based on the signal value transferred fromthe radiographic image capturing apparatus, wherein the notifying devicenotifies an operator of the fact that the channel is being switched, atleast once, while the radiographic image capturing apparatus isswitching the channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the appended drawings, andthus are not intended as a definition of the limits of the presentinvention, and wherein:

FIG. 1 is a perspective view of a radiographic image capturingapparatus.

FIG. 2 is a block diagram illustrating an equivalent circuit of theradiographic image capturing apparatus.

FIG. 3 illustrates exemplary extraction of signal values for preview.

FIG. 4 illustrates an exemplary configuration of a radiographic imagecapturing system according to this embodiment.

FIG. 5 illustrates another exemplary configuration of the radiographicimage capturing system according to this embodiment.

FIG. 6 illustrates a mobile terminal, carried by an operator,functioning as a console.

FIG. 7 illustrates an exemplary message appearing on a display device.

FIG. 8 illustrates another exemplary message appearing on the displaydevice.

FIG. 9 illustrates another exemplary message appearing on the displaydevice.

FIG. 10 illustrates another exemplary message appearing on a displaydevice.

PREFERRED EMBODIMENT OF THE PRESENT INVENTION

With reference to the drawings, an embodiment of a radiographic imagecapturing system according to the present invention will now bedescribed.

In the following description, the radiographic image capturing apparatusis of portable type and includes a sensor panel (not shown) havingplural radiation detecting elements 7 two-dimensionally arranged thereon(see FIG. 2, which will be described below) in a housing 2 (see FIG. 1,which will be described below). Alternatively, the radiographic imagecapturing apparatus may be, for example, of a dedicated or stationarytype having a sensor panel integrated with a supporting base.

[Configuration of Radiographic Image Capturing Apparatus]

The configuration of the radiographic image capturing apparatus will nowbe described. FIG. 1 is a perspective view of the radiographic imagecapturing apparatus. FIG. 2 is a block diagram illustrating anequivalent circuit of the radiographic image capturing apparatus. Aradiographic image capturing apparatus 1 has a two-dimensional matrix ofradiation detecting elements 7 (see FIG. 2) disposed on a sensorsubstrate (not shown) in a housing 2 (see FIG. 1).

With reference to FIG. 1, the radiographic image capturing apparatus 1includes a power switch 25, a toggle switch 26, a connector 27, and anindicator 28 which are disposed on one side of the housing 2. Thehousing 2 is provided with an antenna 29 (see FIG. 2, which willdescribed below) on, for example, the opposite side (not shown) of thehousing 2 for wireless communications with an external device.

As shown in FIG. 2, radiation detecting elements 7 are connected to biaslines 9. A bias power supply 14 applies a reverse bias voltage via thebias lines 9 and their connections 10 to the radiation detectingelements 7. The radiation detecting elements 7 are also connected to therespective thin film transistors (TFTs) 8, which function as switchingelements. Each TFT 8 is connected to the corresponding signal line 6.The radiation detecting element 7 generates electric charges inproportion to the dose of the received radiation.

In a scan driving unit 15, on-stage voltage or off-state voltage isapplied from a power supply circuit 15A to a gate driver 15B via a line15C and then distributed to scanning lines 5(L1) to 5(Lx). The off-statevoltage applied to each TFT 8 via the corresponding scanning line 5 putsthe TFT 8 into the off-state, resulting in disconnection between thecorresponding radiation detecting element 7 and the corresponding signalline 6 to accumulate electric charge in the radiation detecting element7. In contrast, the on-state voltage applied to each TFT 8 via thecorresponding scanning line 5 puts the TFT 8 into the on-state,resulting in the release of the electric charge accumulated in thecorresponding radiation detecting element 7 to the corresponding signalline 6.

Each signal line 6 is connected to the corresponding readout circuit 17in a readout IC 16. In order to read signal values D, the gate driver15B sequentially applies the on-stage voltage to the scanning lines5(L1) to 5(Lx). The on-stage voltage applied puts the TFTs 8 into theon-state, which causes the electric charges to flow from the radiationdetecting elements 7 into the readout circuits 17 via the TFTs 8 and thesignal lines 6. Each amplifying circuit 18 outputs a voltage value inproportion to the electric charge received.

Correlated double sampling circuits 19 (CDSs in FIG. 2) each read thevoltage value output from the corresponding amplifying circuit 18 as ananalog signal value D and sequentially send the analog signal value D toan A/D converter 20 via an analog multiplexer 21. The analog signalvalues D are sequentially converted into digital signal values D at theA/D converter 20 and the digital signal values are sequentially storedin a storage unit 23.

A control unit 22 may be a computer provided with a not-shown centralprocessing unit (CPU), read only memory (ROM), random access memory(RAM) and input/output interface, each being connected to a bus.Alternatively, the control unit 22 may be a field programmable gatearray (FPGA). Alternatively, the control unit 22 may include a dedicatedcontrol circuit.

The control unit 22 is connected to the storage unit 23, a built-inpower supply 24, and a communication unit 30. The storage unit 23includes a static RAM (SRAM), synchronous DRAM (SDRAM), or NAND flashmemory. The built-in power supply 24 includes a lithium ion capacitor.The communication unit 30 is configured to communicate with an externaldevice through a wireless or wired network via the antenna 29 orconnector 27.

As described above, the control unit 22 controls the application ofreverse bias voltage to each radiation detecting element 7 from the biaspower supply 14, controls the operations of the scan driving unit 15 andthe readout circuits 17 to read signal values D from radiation detectingelements 7 to store the read signal values in the storage unit 23, andtransfers the stored signal values D to an external device through thecommunication unit 30.

After reading the signal values D from the radiation detecting elements7, the control unit 22 of the radiographic image capturing apparatus 1according to this embodiment extracts a predetermined portion of theread signal values D as signal values Dpre for preview, transfers theextracted signal values Dpre for preview to a console C prior to theother signal values D, and then transfer the other signal values D tothe console C. Alternatively, the control unit 22 may transfer all thesignal values D to the console C without extracting the signal valuesDpre for preview.

For example, the signal values Dpre for preview (shaded portions) areextracted from all the read signal values D(n, m), as shown in FIG. 3:The signal values D(n, m) read from the radiation detecting elements 7connected the scanning lines 5 may be extracted as signal values Dprefor preview every predetermined number of scanning lines 5 (fourscanning lines in FIG. 3).

In FIG. 3, L1 and L2 represent scanning lines 5(L1) and 5(L2) in FIG. 2,respectively. D(n, m) represents a signal value D read from a radiationdetecting element 7(n, m), which is at row “n” and column “m” in thematrix of radiation detecting elements 7. Alternatively, the signalvalues Dpre for preview may be extracted by any other scheme, forexample, signal values Dpre for preview may be extracted every 3×3 or4×4 matrix of radiation detecting elements 7 among the signal values D.

[Radiographic Image Capturing System]

A radiographic image capturing system 100 according to this embodimentwill now be described. The radiographic image capturing system 100 maybe installed in, for example, an imaging room RA and/or a front room RB,as shown in FIG. 4. Alternatively, the radiographic image capturingsystem 100 may be installed in a medical cart 70, as shown in FIG. 5.

For the radiographic image capturing system 100 installed in the imagingroom RA and the like, the radiographic image capturing apparatus 1 maybe placed in, for example, a cassette holder 51H of an imaging platform51, as shown in FIG. 4. The imaging platform 51A in FIG. 4 represents animaging platform used to image a standing subject. The imaging platform51B represents an imaging platform used to image a lying subject.Alternatively, the radiographic image capturing apparatus 1 may beplaced, for example, between a subject (not shown) lying on a top panelof the imaging platform 51B, which is used to image a lying subject, andthe top panel.

The imaging room RA is provided with at least one radiation generatingapparatus 52, which emits radiation toward the radiographic imagecapturing apparatus 1 through a subject (not shown). The imaging room RAis also provided with an access point 54 having an antenna 53. Theaccess point 54 relays communications between devices inside and outsidethe imaging room RA through a wireless or wired network.

The communications between the radiographic image capturing apparatus 1and the access point 54 according to this embodiment are performedthrough a wireless network between the antenna 29 (see FIG. 2) of theradiographic image capturing apparatus 1 and the antenna 53 (see FIG. 4)of the access point 54. The signal values D or the signal values Dprefor preview, which are transferred from the radiographic image capturingapparatus 1 to the console C through a wireless network, as describedabove, are received by the access point 54 and then sent to the consoleC from the access point 54.

The access point 54 according to this embodiment is provided with achannel interference detecting device 61 and a channel switchcontrolling device 62, which will be described below. The access point54 is connected to a generator 55 of the radiation generating apparatus52 and to the console C, and relays communications among theradiographic image capturing apparatus 1, the console C, and thegenerator 55 of the radiation generating apparatus 52.

The access point 54 is connected to in-hospital systems, such as RIS, ahospital information system (HIS) and a picture archiving andcommunication system (PACS), via a network (not shown). The network maypartially include wireless communications.

The generator 55 of the radiation generating apparatus 52 controls theradiation generating apparatus 52 to emit radiation in a dose inproportion to an X-ray tube voltage, an X-ray tube current, orirradiation time (or mAs value) set by an operator or radiologicaltechnician.

The front room RB (also referred to as an operation room) is providedwith an operator station 57 of the radiation generating apparatus 52.The operator station 57 is provided with an exposure switch 56 which isused by an operator, such as a radiological technician, to instruct thegenerator 55 to start emitting radiation. The front room RB is alsoprovided with the console C with a built-in computer. The console C maybe installed outside the imaging room RA and front room RB or in anyother room.

The console C is provided with a screen CA of a cathode ray tube (CRT)or liquid crystal display (LCD) and is connected to an input unit CB,such as a mouse or a keyboard. The console C is also connected to astorage unit CS composed of a hard disk drive (HDD) or has a built-instorage unit CS.

In contrast, the radiographic image capturing system 100 may include themedical cart 70 on which the radiation generating apparatus 52 and theconsole C are mounted, as shown in FIG. 5. The medical cart 70 is movedto a sickroom R1 for imaging. In this case, the generator 55 of theradiation generating apparatus 52 (not shown in FIG. 5) and the accesspoint 54 including the channel interference detecting device 61 and thechannel switch controlling device 62 are housed in the main body of themedical cart 70.

In this case, the radiographic image capturing apparatus 1 is placedbetween a bed BE and a subject (patient) H, as shown in FIG. 5, or isapplied to the body of the patient. In this case, an operator T, such asa radiological technician, also operates the exposure switch 56 to emitradiation from the radiation generating apparatus 52 to capture animage. After the capture, signal values Dpre for preview are transferredfrom the radiographic image capturing apparatus 1 to the console Cthrough a wireless network.

[Configuration of the Console C]

The console C may be a desk-top or note computer, as shown in FIGS. 4and 5. Alternatively, the console C may be, for example, a mobileterminal, as shown in FIG. 6, which is carried by the operator T, suchas a radiological technician. The console C mentioned in the followingdescription may be a desk-top or note computer (see FIGS. 4 and 5) or amobile terminal (see FIG. 6).

For the console C of a mobile terminal (see FIG. 6), communicationsbetween the access point 54 and the console C are performed through awireless network. For the console C of a desk-top or note computer (seeFIGS. 4 and 5), the communications between the access point 54 and theconsole C may be performed through a wireless or wired network.

The console C generates a radiographic preview image ppre (not shown)based on the transferred signal values Dpre for preview received fromthe radiographic image capturing apparatus 1 after imaging, and displaysthe generated radiographic preview image ppre on the screen CA. Theoperator T, such as a radiological technician, watches the radiographicpreview image ppre appearing on the screen CA of the console C anddetermines the necessity for re-imaging.

The console C according to this embodiment functions as a display devicethat can display a radiographic image (the radiographic preview imageppre in the above case) generated based on the signal values transferredfrom the radiographic image capturing apparatus 1 (the signal valuesDpre for preview in the above case). In the following description, theconsole C is referred to as the “display device C” when it functions asa display device. Alternatively, the display device may be separatedfrom the console C.

After the reception of the signal values Dpre for preview, as describedabove, the console C receives the remaining signal values D (i.e.,signal values D other than the signal values Dpre for preview) from theradiographic image capturing apparatus 1 and then reconstructs all thesignal values D from the remaining signal values D and the signal valuesDpre for preview. The console C performs image processing, such as gaincorrection, defective pixel correction, or gradation processing suitablefor imaged portions, on the reconstructed signal values D to generate aradiographic image p (not shown). The console C according to thisembodiment also displays the generated radiographic image p on thescreen CA. The console C may omit display of the radiographic image p onthe screen CA in some cases.

[Radiographic Image Capturing System (Continued)]

As described above, the radiographic image capturing system 100according to this embodiment (see FIGS. 4 and 5) includes theradiographic image capturing apparatus 1, the display device C (theconsole C in this embodiment), the channel interference detecting device61, and the channel switch controlling device 62. The processes to beperformed in the channel interference detecting device 61, the displaydevice C, and the channel switch controlling device 62 will now bedescribed, together with the operation of the radiographic imagecapturing system 100 according to this embodiment.

For example, 2.4 GHz and 5 GHz bands each have multiple channels definedfor wireless communications over a wireless LAN, as is well known. Thechannel interference detecting device 61 and the channel switchcontrolling device 62 according to this embodiment have non-overlappingfrequency channels preliminarily defined for each band (channels 1, 6,11, and 14 for 2.4 GHz band, for example). These channels are used for awireless transfer of the signal values D (including the signal valuesDpre for preview, the same applies hereinafter) from the radiographicimage capturing apparatus 1.

Since channels for each band depend on countries, a list of channelsavailable in a country in which the radiographic image capturing system100 is used may be displayed on, for example, the screen CA of thedisplay device C, although not shown in the drawing. A radiologicaltechnician may select one channel used for a wireless transfer of thesignal values D from the radiographic image capturing apparatus 1 fromthe list. Information on the selected channel may be sent from thedisplay device C to the channel interference detecting device 61 and/orthe channel switch controlling device 62 to set the selected channel inthe channel interference detecting device 61 and/or the channel switchcontrolling device 62.

The channel interference detecting device 61 can detect radiointerference in a channel used for wireless communications at the accesspoint 54. The channel interference detecting device 61 measures a radiointerference level σ at each channel in use and detects the occurrenceof radio interference at an observed radio interference level equal toor greater than a threshold σth, for example.

Upon detection of radio interference, the channel interference detectingdevice 61 according to this embodiment sends a signal indicating thedetection of radio interference (hereinafter referred to as an“interference detection signal”) to the display device C. The channelinterference detecting device 61 may detect radio interference only fora channel reserved for use. Alternatively, the channel interferencedetecting device 61 may also detect radio interference for otherchannels.

Although the channel interference detecting device 61 may be separatedfrom the access point 54, the channel interference detecting device 61according to this embodiment is disposed at the access point 54, asshown in FIGS. 4 and 5 because the channel interference detecting device61 detects radio interference at each channel used for wirelesscommunications at the access point 54, as described above.

For example, a radio interference level σ, which is measured by thechannel interference detecting device 61 for each channel, appears onthe screen CA of the display device C so that the operator orradiological technician can confirm it, though the illustration thereofis omitted.

The channel interference detecting device 61 according to thisembodiment can detect interference waves from predetermined radars, suchas a weather radar (i.e., radio waves from predetermined radars requiredto avoid interference through DFS by IEEE802.11a, the same applieshereinafter) during detection of radio interference, as described above.Upon detection of interference waves from a predetermined radar, such asa weather radar, the channel interference detecting device 61 accordingto this embodiment sends a signal indicating the detection ofinterference waves from the radar (hereinafter referred to as a “DFSdetection signal”) to the display device C.

Upon reception of an interference detection signal or a DFS detectionsignal from the channel interference detecting device 61, the displaydevice C sends an instruction signal for channel switching to thechannel switch controlling device 62. In response to the switchingsignal, the channel switch controlling device 62 switches the channelused for a wireless transfer of the signal values D from theradiographic image capturing apparatus 1 to another channel.

Upon reception of the interference detection signal from the displaydevice C, the channel switch controlling device 62 according to thisembodiment, for example, instructs the channel interference detectingdevice 61 to send information on the radio interference level σ measuredfor each predetermined channel (or measure and send the radiointerference level σ of each predetermined channel), and switches thecurrent channel to another channel selected as having a lower radiointerference level σ, for example, the lowest level, based on theinformation.

This configuration facilitates a wireless transfer of signal values Dfrom the radiographic image capturing apparatus 1 since the post-switchchannel has a lower radio interference level σ than that of the currentchannel. In the following description, the channel switch controllingdevice 62 switches the current channel to another channel with a lowerradio interference level σ. Alternatively, for example, the channelswitch controlling device 62 may switch the current channel to anotherchannel in accordance with a predetermined priority.

The radiographic image capturing system 100 according to this embodimentis provided with a notifying device that gives notices to an operator ofthe radiographic image capturing system 100. In the followingdescription, the notifying device is integrated with the display deviceC and sends a message to the screen CA of the display device C.Alternatively, the notifying device may make a sound with a speaker (notshown) or generate vibration with a vibrator (not shown) fornotification.

Just like a notifying device configured to send messages, a notifyingdevice configured to make a sound or generate vibration allows theoperator to properly recognize that the channel is under the switchingoperation, for example, when the operator notices the sound orvibration. The notifying device may be separated from the display deviceC.

Upon reception of an interference detection signal from the channelinterference detecting device 61, as described above, the display deviceC sends a switching signal to the channel switch controlling device 62.While a channel switch controlling device 61 is switching the channel asdescribed above, the notifying device displays, for example, a messageA1 “CHANNEL IS BEING CHANGED” on the screen CA of the display device C(see FIGS. 4 to 6), as shown in FIG. 7, to notify the operator orradiological technician that the channel is under the switchingoperation.

As described above, while the channel switch controlling device 62 isswitching the channel used for a wireless transfer of the signal valuesD from the radiographic image capturing apparatus 1, the notifyingdevice sends a message that the channel is under the switchingoperation. This configuration allows the operator or radiologicaltechnician to properly recognize that the channel is being switched.

As described above, it takes about one minute to switch a channel overthe wireless LAN, for example. The message A1 “CHANNEL IS BEINGCHANGED”, as shown in FIG. 7, may appear together with a message A2“CHANNEL CHANGE TAKES ABOUT ONE MINUTE”, for example, indicating thatthe time t is required to switch the channel. This configuration allowsthe operator or radiological technician who watches the message A2 toproperly recognize that it takes about one minute to switch the channel.

Alternatively, the elapsed time from the start of channel switching, forexample, may be indicated in the form of, for example, a message or aprogress bar (not shown), in place of the message A2 indicating the timet required to switch the channel (for example, one minute), as shown inFIG. 7, or together with the message A2. This configuration allows theoperator to recognize how much more time it takes to switch the channelproperly and readily.

As described above, the notifying device may indicate that the channelis under the switching operation in the form of a message on the screenCA. Alternatively, the notifying device may indicate it in the form ofsound or vibration (in particular, if the mobile terminal (see FIG. 6)is a display device C integrated with the notifying device), asdescribed above, together with or in place of the message.

Keeping on making a sound or generating vibration for about oneconsecutive minute during which the channel switch controlling device 62is switching the channel, as described above, may hinder the operationsof the operator or radiological technician. To avoid the problem, thenotifying device may make a sound or generate vibration for only apredetermined period of time from the detection of radio interference bythe channel interference detecting device 61. After the stop for awhile, the notifying device resumes making a sound or generatingvibration at the completion of channel switching by the channel switchcontrolling device 62.

In this case, the way in which the notifying device makes a sound orgenerates vibration at the completion of channel switching by thechannel switch controlling device 62 may be different from that at thedetection of radio interference by the channel interference detectingdevice 61 to facilitate distinction between them. This configurationallows the operator or radiological technician to distinguish thedetection of radio interference by the channel interference detectingdevice 61 from the completion of channel switching.

Advantageous Effects

As described above, the channel switch controlling device 62 switchesthe channel when the channel interference detecting device 61 detectsradio interference or interference waves from a predetermined radar,such as a weather radar. The radiographic image capturing system 100according to this embodiment allows the notifying device to send amessage to the screen CA of the display device C, makes a sound, orgenerates vibration during channel switching to notify an operator orradiological technician that the channel is under the switchingoperation. This configuration allows the operator or radiologicaltechnician to properly recognize that the channel is being switched.

As described above, the display device C displays a radiographic image por radiographic image ppre for preview, which are generated based on thesignal values D or signal values Dpre for preview transferred from theradiographic image capturing apparatus 1. The display device C is alwaysused by the operator or radiological technician during imaging.Accordingly, if the notifying device is integrated with the displaydevice C always used in imaging, notification of currently-executedchannel-switching is properly sent to operator and the operator, who canproperly recognize that the channel is being switched.

Upon occurrence of radio interference in the radiographic imagecapturing system 100, as shown in FIG. 4 or 5, for example, theradiographic image capturing system 100 suspends transfer of the signalvalues D from the radiographic image capturing apparatus 1 and switchesthe channel used for the transfer. Meanwhile, the operator orradiological technician does not know the reason for the suspension ofthe transfer of the signal values D, is hindered in his/her work,mistakenly believes that the cause of the suspension lies in a defect ofthe system, and may perform an unnecessary operation or processing. Theradiographic image capturing system 100 can effectively prevent such anunnecessary operation or processing to ensure that imaging operationsare performed properly.

[Variations]

As described above, the notifying device in the radiographic imagecapturing system 100 according to this embodiment informs the operatoror radiological technician of a channel under a switching operation sothat the operator or radiological technician can properly recognize thatthe channel is being switched. Different variations are available toensure that the operator or radiological technician can recognize thechannel switching properly.

In the following description, the notifying device sends a message tothe screen CA of the display device C (see FIGS. 4 to 6) to notify theoperator or radiological technician of the switching. Alternatively, thenotifying device may make a sound or generate vibration (if the displaydevice C is a mobile terminal (see FIG. 6), in particular), in place ofor together with the message or is separated from the display device C,as described above.

[Variation 1]

In response to reception of an interference detection signal from thechannel interference detecting device 61 after detection of radiointerference, the notifying device may display a message A3 indicatingthe detection of radio interference on the screen CA of the displaydevice C to inform the operator of such detection, as shown in FIG. 8.In response to reception of a DFS detection signal from the channelinterference detecting device 61 after detection of interference wavesfrom a predetermined radar, such as a weather radar, the notifyingdevice may display a message A4 indicating the detection of radar waveson the screen CA to inform the operator of such detection, as shown inFIG. 9.

These configurations allow the operator or radiological technician toproperly confirm the occurrence of radio interference (message A3) orthe detection of interference waves from a predetermined radar, such asa weather radar (message A4).

[Variation 2]

In response to the detection of radio interference by the channelinterference detecting device 61, the operator or radiologicaltechnician may generate a radiographic image p based on the signalvalues D transferred from the radiographic image capturing apparatus 1.In this case, signal values D should preferably be transferred from theradiographic image capturing apparatus 1 to the console C as early aspossible by switching the channel. Accordingly, the operator willinstruct to switch the channel.

In the case where the detection of radio interference, the operator orradiological technician may prepare imaging of the next patient, ittakes time to receive the next patient in the imaging room RA (see FIG.4) or move the medical cart 70 to the sickroom R1 (see FIG. 5).Accordingly, the operator may determine channel switching to beunnecessary because the operator does not need to hurry up intransferring signal values D from the radiographic image capturingapparatus 1 to the console C.

For example, the data volume of signal values Dpre for previewtransferred from the radiographic image capturing apparatus 1 to thedisplay device C is smaller than that of all the signal values D, asdescribed above (see FIG. 3). In response to the detection of radiointerference at the channel interference detecting device 61, theoperator or radiological technician may prefer immediate transfer of thesignal values Dpre for preview in the current channel to transfer afterthe channel switching for about one minute because the operator candetermine the channel switching to be unnecessary due to earliertransfer of the signal values Dpre for preview transfer.

As described above, the operator or radiological technician maydetermine the channel switching to be necessary or unnecessary,depending on the case, in response to the detection of radiointerference by the channel interference detecting device 61. Thedisplay device C according to the above embodiment sends an instructionsignal for channel switching to the channel switch controlling device 62to switch the channel immediately after the display device C receives aninterference detection signal from the channel interference detectingdevice 61. Alternatively, the display device C according to thisvariation may have the following configuration:

In response to the detection of radio interference at the channelinterference detecting device 61, the notifying device displays amessage A3 indicating the detection of radio interference on the screenCA of the display device C to informs the operator of the detection ofradio interference, as shown in FIG. 8, while the display device Cdisplays a message A5 “DO YOU WANT TO SWITCH CHANNEL?” to ask theoperator or radiological technician for a decision.

In response to the reception of an instruction signal for channelswitching from the operator or radiological technician (i.e., click ofan “OK” button icon B1 in FIG. 8, for example), the display device C maysend a switching signal to the channel switch controlling device 62.

In response to the reception of an instruction signal for non-channelswitching from the operator or radiological technician (i.e., click of a“Cancel” button icon B2 in FIG. 8, for example), the display device Cdoes not send a switching signal to the channel switch controllingdevice 62.

This configuration allows the display device C to switch or not switchthe channel in line with the decision of the operator or radiologicaltechnician, thus increasing the usability of the radiographic imagecapturing system 100 for operators. The message A2 indicating the time trequired to switch a channel (about one minute, for example), as shownin FIG. 8, allows the operator to determine the necessity for switchingthe channel in consideration of the time t required to switch thechannel.

[Variation 3]

As described above, the IEEE802.11a standard requires to avoidinterference over a wireless LAN through DFS on the detection ofinterference waves from a predetermined radar, such as a weather radar.In conformance with the standard, the channel interference detectingdevice 61 must switch the channel immediately after the detection of,not radio interference, but interference waves from a predeterminedradar, such as weather radar.

In response to the reception of a DFS detection signal from the channelinterference detecting device 61 after detection of interference wavesfrom a predetermined radar, the display device C according to thisembodiment sends an instruction signal for channel switching to thechannel switch controlling device 62 to switch the channel immediately.When receiving the switching signal, the channel switch controllingdevice 62 switches the channel used for a wireless transfer of thesignal values D from the radiographic image capturing apparatus 1, asdescribed above.

This configuration allows the channel used for a wireless transfer ofthe signal values D from the radiographic image capturing apparatus 1 tobe switched to another channel immediately after the detection ofinterference waves from a predetermined radar, such as a weather radar,at the channel interference detecting device 61, thus properly avoidinginterference between interference waves from a predetermined radar andsignal values D transferred from the radiographic image capturingapparatus 1.

Unlike the detection of radio interference at the channel interferencedetecting device 61 in Variation 2, the detection of interference wavesfrom a predetermined radar at the channel interference detecting device61 in Variation 3 allows the display device C to transmit a switchingsignal to the channel switch controlling device 62 without asking theoperator or radiological technician for a decision, in response to thereception of a DFS detection signal from the channel interferencedetecting device 61.

In response to the detection of interference waves from a predeterminedradar at the channel interference detecting device 61, the notifyingdevice displays a message A4 “RADAR WAVE DETECTED” or a message A6“CHANNEL IS TO BE CHANGED” (together with the message A2 indicating thetime t required to switch a channel (about one minute, for example)) onthe screen CA of the display device C, as shown in FIG. 9, as describedabove. To reinforce the recognition of the operator or radiologicaltechnician that the channel is to be switched, without asking theoperator for a decision, the notifying device may, for example, displaya background BG in yellow to call for attention of the operator.

In this case, neither “OK” button icon B1 nor “Cancel” B2 button icon(see FIG. 8) is displayed, as shown in FIG. 9, because the notifyingdevice does not need to ask the radiological technician for a decision,as described above.

[Variation 4]

Variations 1 to 3 (see FIGS. 8 and 9) relates to the messages A3 to A6displayed at the start of channel switching. The above embodiment (seeFIG. 7) relates to the message A1 during channel switching. Thenotifying device according to the above embodiment may make a sound orgenerate vibration upon completion of channel switching at the channelswitch controlling device 62, as described above.

In response to the completion of channel switching by the channel switchcontrolling device 62, for example, the notifying device sends a messageA7 “CHANNEL CHANGE COMPLETED” to the screen CA of the display device C,as shown in FIG. 10, to notify the operator or radiological technicianof the completion of channel switching. Alternatively, the notifyingdevice may make a sound or generate vibrations, as described above.

This configuration allows the operator or radiological technician, whowatches the message A7 on the screen CA of the display device C, toproperly recognize the completion of channel switching. An “OK” buttonicon B3 may appear, as shown in FIG. 10, to prompt the operator to clickit. This configuration further reinforces the recognition of thecompletion of channel switching.

In the above embodiment and variations, the channel interferencedetecting device 61 sends an interference detection signal and/or a DFSdetection signal to the display device C, and the display device C sendsa switching signal to the channel switch controlling device 62, asneeded. In other words, the switching signal is sent in line with thedecision of the operator or radiological technician upon the detectionof radio interference, whereas the switching signal is sentunconditionally upon the detection of interference waves from apredetermined radar, such as a weather radar. Alternatively, the channelinterference detecting device 61 and the display device C may have anyother configuration.

The above embodiment and variations have been described, but they shouldnot be construed to limit the present invention, and variousmodifications may be made without departing from the scope of theinvention.

The present U.S. patent application claims a priority under the ParisConvention of Japanese patent application No. 2016-026571 filed on Feb.16, 2016, application which is incorporated herein by reference.

What is claimed is:
 1. A radiographic image capturing system comprising:a radiographic image capturing apparatus which wirelessly transfers asignal value read from each of a plurality of radiation detectingelements; a channel switch controlling device adapted for switching achannel used for wirelessly transferring the signal value from theradiographic image capturing apparatus to another channel; a notifyingdevice which gives a notice to an operator who operates the radiographicimage capturing system; and a display device which displays aradiographic image generated based on the signal value transferred fromthe radiographic image capturing apparatus, wherein the notifying devicenotifies the operator that the channel is being switched, at least once,while the radiographic image capturing apparatus is switching thechannel.
 2. The radiographic image capturing system according to claim1, wherein the notifying device notifies an operator of time required toswitch the channel, in addition to the fact that the channel is beingswitched.
 3. The radiographic image capturing system according to claim1, wherein the channel switch controlling device switches the channelwhen receiving a switching signal which gives an instruction ofswitching of the channel, the switching signal being transmitted fromthe display device.
 4. The radiographic image capturing system accordingto claim 1, wherein the channel switch controlling device is disposed atan access point adapted for receiving the signal value wirelesslytransferred from the radiographic image capturing apparatus.
 5. Theradiographic image capturing system according to claim 1, wherein thenotifying device gives the notice by any one of a message, sound andvibration, or by a combination of two or three of the message, sound andvibration.
 6. The radiographic image capturing system according to claim1, wherein when the channel switch controlling device completesswitching of the channel, the notifying device notifies an operator ofthe fact that the switching of the channel is completed by any one of amessage, sound and vibration, or by a combination of two or three of themessage, sound and vibration.
 7. The radiographic image capturing systemaccording to claim 1, wherein the notifying device is integrated withthe display device and the notice is displayed in the display device. 8.The radiographic image capturing system according to claim 1, whereinthe display device is a console adapted for displaying the radiographicimage.
 9. The radiographic image capturing system according to claim 1,further comprising a channel interference detecting device adapted fordetecting radio interference, wherein when the channel interferencedetecting device detects the radio interference, the notifying devicenotifies an operator of the fact that the radio interference isdetected.
 10. The radiographic image capturing system according to claim9, wherein the channel interference detecting device is adapted fordetecting an interference wave from a predetermined radar, and when thechannel interference detecting device detects the interference wave fromthe predetermined radar, the display device immediately transmits aswitching signal which gives an instruction of switching of the channelto the channel switch controlling device.
 11. The radiographic imagecapturing system according to claim 10, wherein when the channelinterference detecting device detects the interference wave from thepredetermined radar, the notifying device notifies an operator of thefact that the interference wave from the radar is detected.
 12. Theradiographic image capturing system according to claim 9, wherein thechannel interference detecting device is disposed at an access pointadapted for receiving the signal value wirelessly transferred from theradiographic image capturing apparatus.
 13. The radiographic imagecapturing system according to claim 9, wherein the channel interferencedetecting device is adapted for measuring a radio interference level ateach channel available for wireless communication, and the channelswitch controlling device switches the channel used for wirelesslytransferring the signal value to another channel having a lower radiointerference level measured by the channel interference detectingdevice.
 14. The radiographic image capturing system according to claim1, further comprising a channel interference detecting device adaptedfor detecting radio interference, wherein when the channel interferencedetecting device detects the radio interference, the display devicetransmits the switching signal to the channel switch controlling devicein response to an input of a signal which gives an instruction ofswitching of the channel.
 15. The radiographic image capturing systemaccording to claim 1, further comprising a channel interferencedetecting device adapted for detecting radio interference, wherein whenthe channel interference detecting device detects the radiointerference, the display device immediately transmits the switchingsignal to the channel switch controlling device.